B1.2 - What Happens In a Cell

Question 1

what is DNA (DeoxyriboNucleiAcid)

Answer 1

genetic code that instructs cells on what substances to make

Question 2

what are chromosomes

Answer 2

a single strand of tightly coiled DNA, located in the nuclei of cells

Question 3

what are alleles

Answer 3

a different form of gene

Question 4

what is a nucleus

Answer 4

DNA contained within a nucleur envelope

Question 5

what is the role of a cell membrane

Answer 5

the cell membrane controls the movement of substances in and out of the cell

Question 6

what is the role of the nucleus

Answer 6

it carries genetic information

Question 7

what happens at the cytoplasm

Answer 7

the cytoplasm is where many chemical reactions happen

Question 8

chromosomes are made out of what chemical?

Answer 8

DNA

Question 9

what is a section of a chromosome called

Answer 9

gene

Question 10

what is a gene

Answer 10

a section of chromosome that codes for making particular proteins (and therefore controls inherited characteristic)

Question 11

what is a double helix

Answer 11

the DNA molecular structure

Question 12

what is a sugar phosphate backbone

Answer 12

two strands forming the uprights of the ladder. these strands support the base pairs but do not carry genetic information

Question 13

what are complimentary bases

Answer 13

the two connected bases of the DNA ladder that keep the two strands of DNA molecule together

Question 14

what are bases

Answer 14

the rungs of the DNA. these are the part of the DNA that carry the genetic information

Question 15

what are the 4 types of DNA bases

Answer 15

A and T, C and G

Question 16

what is a polymer

Answer 16

a polymer is a molecule made up of many repeating units. proteins, starch and polythene are all polymers

Question 17

what is a polynucleotide

Answer 17

a polynucleotide is when its subnits (monomers) are nucleotides

Question 18

what are proteins

Answer 18

proteins are polymers made up of small molecules (molnomers) called amino acids. different proteins contain different sequences of amino acids

Question 19

different amino acid chains are folded to form specific 3D shapes. what does this determine

Answer 19

this determines their function

Question 20

what is needed to make amino acids

Answer 20

nitrogen is needed

Question 21

where is nitrogen found

Answer 21

nitrogen is found in plants (from air and fertiliser)

Question 22

what does protein synthesis involve

Answer 22

protein synthesis involves transcription and translation

Question 23

where does transcription occur

Answer 23

transcription occurs in the nucleus of the cell

Question 24

what is the process of transcription

Answer 24

1) the section of DNA that codes for a protein ‘unzips’.
2) a complementary strand of messenger RNA (mRNA) forms on one DNA strand.
3) the mRNA peels off and moves into the cytoplasm

Question 25

where does translation occur

Answer 25

translation occurs in the cytoplams

Question 26

what is the process of translation

Answer 26

1) the mRNA attaches to a ribosome | 2) transfer RNA (tRNA) brings the correct amino acid for each triplet code

Question 27

what are the 3 components that make up a nucleotide

Answer 27

a sugar, a phosphate group and a base

Question 28

what is the rate of enzyme action affected by

Answer 28

the rate of enzyme action is affected by temperature, pH, substrate concentration and enzyme concentration

Question 29

how does high temperature and deviation from the optimum pH affect enzymes

Answer 29

high temperature and deviation from the optimum pH causes enzymes to lose their shape and become denatured

Question 30

how does low temperature affect enzymes

Answer 30

low temperatures slow down the rate of reaction

Question 31

how does pH levels affect enzymes

Answer 31

different enzymes have different pH levels depending on where they act in the body

Question 32

what is the optimum temperature for human enzymes

Answer 32

37 degrees celcius as this is normal human internal body temperature

Question 33

what happens to enzyme activity if substrate concentration increases

Answer 33

as substrate concentration increases, the rate of enzyme activity increases to the point where all the enzymes present are being used

Question 34

what happens to enzyme activity if enyme concentration increases

Answer 34

as enzyme concentration increases, the rate of enzyme activity increases to the point where all the substrate present is being used

Question 35

what are enzymes

Answer 35

enzymes are biological catalysts and increase the rate of chemical reactions inside organisms

Question 36

what are enzymes made out of

Answer 36

enzymes are made out of proteins

Question 37

why is the amino acid chain folded

Answer 37

the amino acid chain is folded to make a shape into which substrates (substances) can fit

Question 38

what is the active site

Answer 38

the active sit is the place where the substrate fits

Question 39

what can fit into the active site

Answer 39

only substrate molecules with the correct shape and fit

Question 40

what happens when enzymes lose their shape

Answer 40

enzymes are denatured when they lose their shape

Question 41

what happenes when an enzyme is denatures

Answer 41

the substrate no longer fits and the enzyme does not work

Question 42

what is the role of a biological catalyst

Answer 42

it is made up of proteins and speeds up the chemical reactions inside all cells, without being used up